We would like to let you know that, parent task item’s start date and end date will get update based on the child task item’s start date and end date. Currently this is the behavior of the parent item in Gantt control. If there are many child task item, from which parent item will take minimum start date and maximum end date. If this is not related to your query, we request you to share more information about your query and please revert us with the sample along with the replication procedure. This would be helpful for us to serve you better.

Now we have prepared a sample with simple parent and child task item. Please find the sample in the following location.

But at present we are facing some issues in MilestoneMapping property and we have confirmed this as bug and logged a report on this. Also we have created a support incident under your account to track the status of this issue.

At present to meet your requirement, we request you to provide “DurationMapping” property. Please provide Duration value as “1”, if you give same date for both StartDate and EndDate in the data source.

But at present we are facing some issues in MilestoneMapping property and we have confirmed this as bug and logged a report on this. Also we have created a support incident under your account to track the status of this issue.

At present to meet your requirement, we request you to provide “DurationMapping” property. Please provide Duration value as “1”, if you give same date for both StartDate and EndDate in the data source.